We have presented a new layout technique for visualizing very large directed graphs in 3D hyperbolic space. The H3 technique handles at least two orders of magnitude more data than general graph layout tools. We compute a variation of a cone tree layout based on a spanning tree, and only draw nontree links for selected nodes on demand. In our hyperbolic variation of the cone tree algorithm, we draw a dense neighborhood around the focus of interest by laying out nodes on a spherical cap covering the mouth of the cone rather than its perimeter. We have achieved promising results graphs of tens of thousands of nodes in application domains as the link structure of the Web, Unix file systems, and function call graphs.